The invention relates to a system, method and computer program product for displaying and/or compressing digital data in general and to a system, method and computer program product for displaying characters assigned to code symbols in particular.
Graphic displaying is a key element of user-machine interfacing in handling digital data. For example, it has become very popular in the last years to communicate by transmitting text messages and also images. The most popular example of this type of communication is an e-mail.
In recent time such a written or more generally speaking visible or non-audible telecommunication has also conquered the field of mobile communication. The most popular example is the so-called short message service (SMS). However, the transmission of e-mails from and to mobile terminals, like mobile phones or personal digital assistants (PDA) is possible too.
Furthermore, an extremely hard world-wide competition between producers and between service providers provides for an ever-increasing demand and supply of services and comfort in telecommunication.
For example it is desirable to transmit and display Japanese, Chinese or Arabic characters with mobile terminals, e.g. to enable an SMS or e-mail contact between people not using Latin characters in there mother tongue. However, such characters should also be displayed when simply loading data, e.g. from an electronic phonebook storing characters or words in the terminal. Those aspects become dramatically important as Asia is expected to be one of the fastest growing markets for telecommunication technologies in the next decades.
However, a limiting factor for such demands is the memory space of the electronic equipment which is most serious for mobile terminals, as on the other hand there is an ever-increasing and obviously counter-acting demand for miniaturizing the terminals, phones and other mobile telecommunication equipment.
Typically, mobile terminals already have pixel-oriented graphic displays which are generally suitable to display nearly any kind of characters and even small images as well as Latin letters. Here, the letters or characters are drawn on the display by creating a pixel-oriented image in a sub-array of pixels of the display. Therefore, letters, characters or images are also stored pictorially, i.e. by storing them as graphic bitmap. When a message is sent from one to another terminal, merely a code sequence comprising a code symbol for each letter is physically transmitted instead of the pictorial representation of the letter. Those code symbols are allocated to an address in the memory of the receiving terminal where the pictorial representation is stored and the letter is transmitted to the display.
Therefore, digital data representing or embodying the letters are typically compressed to save storage space. E.g. runlength encoding or other known compressing algorithms like the Lempel-Ziv-Welch approach or the like are used for this.
However, pixel-oriented compression algorithms involve another serious disadvantage, namely they are highly computer-bound.